AOM-178: Add unit tests for LegacyUIImpl

api/src/main/java/org/openmrs/module/legacyui/api/impl/LegacyUIImpl.java

@@ -225,12 +225,23 @@ public void triggerStateConversion(Patient patient, Concept trigger, Date dateCo
 	 */
 	@Transactional(readOnly = true)
 	public Provider getProviderForUser(User user) {
-		ProviderService ps = Context.getProviderService();
-		Collection<Provider> providers = ps.getProvidersByPerson(user.getPerson(), true);
-		if (providers.isEmpty()) {
-			throw new IllegalStateException("User " + user + " has no provider accounts, unable to create orders");
-		}
-		return providers.iterator().next();
+        if (user == null) {
+            throw new IllegalArgumentException("User cannot be null");
+        }
+
+        if (user.getPerson() == null) {
+            throw new IllegalStateException("User has no associated person record");
+        }
+
+        ProviderService ps = Context.getProviderService();
+
+        Collection<Provider> providers = ps.getProvidersByPerson(user.getPerson(), true);
+
+        if (providers.isEmpty()) {
+            throw new IllegalStateException("User " + user + " has no provider accounts, unable to create orders");
+        }
+
+        return providers.iterator().next();
 	}
 
 	/**

api/src/test/java/org/openmrs/module/legacyui/api/impl/LegacyUIImplTest.java

@@ -0,0 +1,31 @@
+package org.openmrs.module.legacyui.api.impl;
+
+import org.junit.jupiter.api.Test;
+import org.openmrs.User;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+public class LegacyUIImplTest {
+
+    @Test
+    void shouldThrowExceptionIfUserIsNull() {
+
+        LegacyUIImpl service = new LegacyUIImpl();
+
+        assertThrows(IllegalArgumentException.class, () -> {
+            service.getProviderForUser(null);
+        });
+    }
+
+    @Test
+    void shouldThrowExceptionIfProviderNotFound() {
+
+        LegacyUIImpl service = new LegacyUIImpl();
+
+        User user = new User();
+
+        assertThrows(IllegalStateException.class, () -> {
+            service.getProviderForUser(user);
+        });
+    }
+}